Mixed fluorinated phosphate compounds are commonly prepared with long chain fluorinated alcohols or a mix of long chain fluorinated alcohols. These alcohols are expensive and in short supply.
Honda et al., in Macromolecules, 2005, 38, 5699-5705 show that for perfluoroalkyl chains of 8 carbons or greater, orientation of the perfluoroalkyl groups is maintained in a parallel configuration, while reorientation occurs for such chains having 6 carbon atoms or less. Such reorientation decreases surface properties such as receding contact angle. Thus, shorter chain perfluoroalkyls have traditionally not been successful commercially.
Brace and Mackenzie, in U.S. Pat. No. 3,083,224, describe mixed fluoroalkyl phosphates having the formula [CmF2m+1CnH2nO]yPO(OM)3−y where m is 4 to 12, n is 1 to 16, and y is averaged to be 1.0 to 2.5. Brace and Mackenze describe their use as an oil repellent, particularly when y is 2.
It is desirable to improve surfactant performance, such as lowering the surface tension of a coating composition, while using less fluorine and while using a more selective and efficient synthetic process. It is also desirable to impart surface effects to coated surfaces, including increased blocking resistance, increased oil and water repellency, increased soil and stain resistance, increased contact angle, and increased wetting and leveling of a coating.